Universal cord-circuits.



A. J. CARTER.

UNIVERSAL CORD CIRCUITS.

APPLICATION FILED JUNE 6.1914.

Patented Oct. 1, 1918.

25 5Z5 J I 51-72 2".

.5 M 3 QQQM.

u e e ms ane henna ALVA J. :CAR'QEB; memento, .lLLlNOISQ Assienoa'ioKEIiLOGG-S WIT CHBOAR-D Ann SUEPLY coiurjenmlor CI-I'IQAGQ, :LIJLLINOIS,A ooRroRATIon or ILLINOIS.

To allnuhom it'may concern Be it known that l,- ALVA Jf Clean ng, ,-acitizen of the United :States of America,

residing in Chicago county of Gook and State of Illinois;have-invented,certalnq new and useful Improvements in Universal Cord-Circuits, of which the follow-mg 11s a specification. i

rMyginvention relates to telephone 7 systems inwhich 1 uniuersalco-rdcircuits are provided for interconnecting telephone lines of differentcharacters such asmagneto and common battery lines, :one of theprincipal objects being to providean improyedcircuit arrangement in "theLcord circuit whereby the connecting plugs may beinsertedxintenchangeably :into lineTjacks vof the two or three-contacttype of common battery lines,

or to three-contact jacks of common battery or magneto-lines and:provide the "proper supervision and talking current supply where needed.My invention :is also particularly useful in connection with UlllVBlSfilcord circuits for lnterchangeably connecting common battery and magnetotelephone lines provided withthree contactjacks having the thimbleconnected to cut-off relays and the other two contacts extending in lineconductors, the cord icircuit being provided with a three-contact plughaningdits third contact connected to' a switching relay :itdapted to beconnected in series iWlth' ithe cut-off relayzand provided with circuitconnectionswhereby the resulting energ ization of the switchmg relay'Wlll connectuts winding to a talkingcontact of the plugiandithus supplytalking current' to thewconnected line,"

providing it is a :common battery line; If

the plugis inserted in a magneto lineithe call signal. a

c'ut-ofi relay thereof will energize although the switching relay willnot, and therefore the switching relay is not operated toHsupply;

talking current. i t

In the preferred embodiment ofinydnl mention, I provide a distinctive"signaling means whereby an! operator can distinguish calls between amagnetoi and common battery line so that 1 'case a' magneto; line Wishesto recall prior to the: removal ofltlie plug from :the answeringfjack,the super-- visory signal will flash in a distinctive man nen'so thatthe operator can readily distinguish when a connected magneto? line "issignaling. whether it s a disconnect ;or reuiiiv uas lrnponn-eracurrs.

"1 S p'ecificatiomof Letters Patent. 'Paflgentedflct 1, Applicationfiled June 6,1914. Serial no. 843346.

Referring now more in detail to.one form of my invention as illustratedin the acoompanying drawing, I [show two common battery'substations Aand D terminatingin the line circuits L andEL and two magnetosubstations B and C terminating inlinecircults L and L respectmely. A1cord circuit ing connection be weensubstationsA and EB,

and C and D 1orconnections 'may be established between A and G, or BandD, orlikewise, connection maybe established be tween two telephonesof like character. At the left of the drawing, I have shown con-Vertible :line circuits Land L for magneto and common battery lines,these line circuits comprising similar apparatus but (liffering only inconnections. y a i The magneto glinc comprises awell-known magnetosubstation B terminating in :a line circuit L, the said "line circuit Lcomprising a cut-ofi relay CO, at line relay LR, a line signals, and themultiple jack J. The line circuit L is so arranged that when the handgenerator at the substation B is operated the line relay "LR isenergized and :then establishes alocking circuitjfor itselfto maintalnthe signal S lighted unt1l an answering plug isfw nserted into the jack,(whereby the cut-off relay ,GO-isenergized. The line cirT cult Lmarranged so that it may beichanged into acommon battery llne c1rcu1tsuch as L by simplyqchanging the connections of the relaysLR and-CO asshown.

' The common battery line comprises a wellknown common batterysubstation A terminatingina line circuit L which comprises alcutbfirelay GOQ'a line relay LRQba-line signal S, and the multiple? jack J.The relay C0 when used ,withu a magnetoline relays and $2001 the cordcircuit E when connection is :made with a line so as to connect thecommon battery Winding CB of the relay AS in circuit with the connectedline.

At the right of the drawing I have illustrated a magneto substation Cand a common battery substation D terminating in line circuits L and LThe line circuit L has the usual line signal S and jacks J 2 which areshown multiply connected. The line circuit L is a twowire line circuitcomprising the cut-off relay-CO line relay LR, line signal S and themultiple jack J Y The cord circuit E comprises the answering and callingplugs P and p which are connected by the heavily marked conductors, thethird contact of each plug having a switching relay as SW or swconnectedto it. These switchingrelays are energized when connection ismade with a common battery line soas to bridge the supervisory relays ASand CS across the connected line. The switching relays SW and 3w have anormally opencontact which is closed when the switchingrelays SW or $10are energized by reason of connection with a common battery line tocross the ring and sleeve contacts of the con .nected plug to connectthe ring and sleeve conductors so as to form a second or-sleeveconductor and also for the purpose of supplying battery for talkingpurposes. hen connection is made with a magneto line these switchingrelays are not energized and thus maintain the magneto windings M or Mbridged across the line. The relays COand Q0 of magneto and commonbattery line circuits L and L are ofdiiferent resistances, relay CObeing sufficiently high to'pre'vent the operation of the relay SW andrelayCO of the common battery line being of a low enough resistance topermit the energizfation of the switching relay SW, but in either casethese relays CO or CO: operate. V

I arrange the supervisory slgnals as SS so that an operator can readilydistinguish what kind of a line isconnected with the corresponding endof the cordcircuit. When a common battery line is connected a switchingrelay as SW is operated, the supervisory signal as SS being thencontrolledthrough the resistance B. This resistance lt'being of.

low enough resistance allows the signal SS to glowbrightly. When amagneto line is 7 connected the switch ng relay lsnot energ zed, and thesupervisory slgnalSS 111-- cluded' in series circuit with itsassociatedwinding CB which is of a higher resistance than its associated'reslstance R so that the signal SS glows less brightly.

. Now if a subscriber on a common battery line wishes .to recall, therelay AS or US as the'case may be,'i s operated to flash the signal SSor SS, when the switchhook is operated or winked at the callingsubstation.

Now if the subscriber 'ona 'magneto liner wishes to recall, the relay ASor CS as the case may be, is operated by current from the hand generatorat the magneto substation and then locks its armature with itsassociated signal connected in series withits associated winding CB.Upon further actuation of thehand generator at the substation, a

flow of alternating current passes through the winding M of theassociated supervisory relayproducing an induced current flow in itsassociated winding OB and causes a flickering of the signal SS or SS, asthe case may be. "Even though thesupervisory relay is locked, when adisconnect signal on the" magneto line is received, a subscriber isstill able to. causea distinctive operation of the signal when he wishesto recall or attract the operators attention. I:

In regard to the various resistance values used in-the control of theswitching and signaling circuits, I have found in practice that with thefollowing values successful operation is secured. Relay GO, 1000 ohms,each winding500 ohms, relay CO" 250 ohms, and relays SWand sec, 100ohms. By using a ohmresistance R and l00 ohms for resistance of. thewinding GB of the supervisory ingrelay sw and cut-off relay CO operate.

' Havingdescribedingeneral the apparatus as'illustratedinthe drawing,the operation of the system will now be described.

Assuming that a call is initiated at the magneto su'bstationB, thesubstation generator is operated, current flowing over a circuit ineluding the line relay :LR which energizes closing a: locking circuitfor itself through its contacts 1 and 2 and contact 10 of the relay Q0.The closing of contact2of relay LR lightsthe signal S which remainslighted due tolthe locking circuit of relay LR. The

operator noting the signal inserts the an-: swering plug P into the ackJ of the calling. line, this-operation connecting the switching relay-SWand cut-off relay CO in series.

This permits the operation of the cutoff.

relay CO from; battery through the winding of the switching] relay SW,through: contactsof the plug P. and jack J, thewinding of cut-off relaytoground. But due to the high resistance of relay CO, as previouslydescribed, 3 the relay SW; .does not operate:

The energization of relay CO opens the locking circult of. the relay LRwhich deinergizes and e'ffaces the signal S andidue to the relay 8w inlt'act that the switching relay does not 111g plug pinto the jack Jclosing a circuit for the cut-Oil relay CO and the switching seriescausing the operation of both of these relays, The operationof cutoffrelay CO extends the talking conductorsof the cord circuit E to thecalled line. The operation of the switching relay aw closes a circuit.for the supervisory si nal SS fromibattery throughthe signal S, normalcontact 4 of the supervisory relay CS, alternate contact 3 ofthe relay,8w through resistance R to ground causing a bright glow of thesupervisory signal SS. The operator their throws her ringing key RK toring the called-for subscriber, and due to the crossing of the sleeveand ring contacts of the plugp by the closing of alternate contact 5 ofthe switching relay aw, battery is supplied tothe called line throughthe relay sw and WllBllthE subscriber answers due to the signal causedbythe actuation of the ringing key RK, currentflows over thecalled linereturning over the tip conductor, alternate'contact 6 of the switchingrelay 810 and the winding GB of the relay CS to ground. This energizesthe relay CS and opens the circuit of the signal 4 SS at normal contact4C, efi'acing the signal.

. relay AS The substations B and D are now connected in conversationalcircuit, said circuit being traced over the heavily marked conductors.When conversation is completed the sub scriber at the calling magnetosubstation B operates his hand generator causing the flow o'f currentthrough thebridged winding M of the relay AS closing its alternatecontact 7, thus establishing a locking circuit for relay AS'tra-ced frombatterythrough the signal SS, alternate contact 7 the normal contacts 8and 9 of the listening keyLK, normal con tact 11 of relay SlV. and theWinding CBof relay AS to ground Thesignal SS is in cluded in circuitwith the winding CB or the so that a dull glow of the lamp SS isobtained which notifies the operator that this signal ;is received froma magneto substation; The disconnect signal from the commonbatterysubstation D is obtained the subscriber at subStation'DLlQP acing hisreceiver, which actinterrupts theflo'w of iciirrent through 'the windingCB of relayCS.

, but rel aysfsw and C0 are still niaintainedenergized over thepreviously traced circuit and upon de'e' nergization ofrelay CS itsnormal contact a is again closed connecting the sigthe jacks J and Jsubscriber-.1) Wishes to recall.

nal SS, ,and resistanceR in series thus lighting thelamp brightly andindicating to the operator that a disconnect signal has been receivedfrom a commonbattery subscriber; The operator now withdraws theanswering and calling plugs and P. from a The Withdrawal of the plug 39effects the restoration of the relay 8w, restoring said relay andefl'acing the signal SS. The relay AS wasenergized and locked up overthelocal circuit including normal contacts 8 and 9 of the listening keyLK and in order to eflect the restoration of the relay AS the operatoractuates the listening'key LK to interrupt the circuit of relay at thenormal contacts 8 and 9 and saidrelay AS restores efi'acing thesignalSS.

Now if the subscriber at substation B wishesito recallorconverse withthe operator before the removalof the answering plug P from the ack acontinued operation of the hand generator at substation 13 transmits analternatingcurrent through the magneto Winding M of the supervisoryrelay AS. An induced currentis set up in the winding GB of supervisoryrelay AS and this winding being included visory signal SS a flickeringefi'ect of-the lamp is produced, notifying the operator that a recall isbeing sent from a magneto substation. Without this distinctive featureof the signal upon recall, the operator would disconnect when a recallwas desired. The operator after having 'conversed with the subscriberthat sent the recall, throws her listening key LK interrupting thecircuit of the relay AS, said relay restoring and etfacing the signalS'S as before described. The recall of the common battery subscriberatsubstation D is caused by the subscribers switch-hook being operated,causing the sig nal SS to flash, notifying the operator'that Now ifacall is initiated from the common battery subscriber A, upon removal ofthe switch-hook at substation A, the line relayLR' is energizedclosingits alternate contact 2' tolight the line signal S. The operatornotingthe'lighted' signal S inserts the answering plug P into the jack JWOtthe calling line. This insertion oitthe plug P into the jack energizesthe cut-01f relay (f -O andthe switching relay 3 SW in series.Responsive to the energization of the switching relay SVV' its alternatecontact 12 is closed-thereby connecting the sleeve and ring contactsotthe plug P so that-jthebattery through the and through alternate contact1301:" relay SW through the common battery winding GB of relay AS toground, causing the energization of the supervisory relay AS; When theswitching relay SW is energized the closing of its alternate contact 13disconnects in circuit with the super relay S'W will flow over thecalling line returniing over the tip conductor the magneto Winding ofthe supervisory relay AS from the cord circuit and connects the commonbattery winding GB of the relay into the jack J 2 0f the magneto line,and the insertion ofthe plug disconnects the line signal S and asthesleeve of the jack J 2 is on open clrcuit, no circuit isestablishedfor the switching relay 8012, this relay remains deenergized andmaintains its magneto Winding M of the calling supervisory relay CS inbridge of the calledline. The operatornow actuates, her ringing key RKto ring the bell of thecalled-for subscriber at magneto substation C,and upon the removal of the receiver at substation C, the lines areconnected in conversational circuit, which may betraced over the heavilymarked conductors. When conversation is completed the subscriber atmagneto substation C operates the hand generator at thesubstation G,causing the signal SS" to light with a dull glow for the same reason aspreviously de scribed and the restoration of the receiver at substationA causes the signal SS to light and glow brightly. The disconnection andrestoration of the apparatus to normal is the same as before described,the operator actuates her listening key LK to interrupt thenormalcontacts l l and 15 to interrupt the circuit of relay CSand elfacesignal SS.

In case of either subscriber wishin to recall before the plugsarewithdrawn the operation of the signals SS and SS are the same aspreviously described" a Should connection be established between thesubstations A and B, the operation of thecircuit can be men -followedfrom the previous description, and i tion be established betweensubstations C and B or to substations of likecharacter such as to commonbattery or. two magneto substations, the operation can also be readilyfollowed from the description already given. a "While I have described'my invention in one specific form and, have given certain values for asuccessful operation, I do not wish to, be limited to the same as Icontemplate changes which will, readily .suggest themselves tothoseskilled in the art, and I aim to cover all such modifications inthe appended claims Having described my invention, what I claim as newand desire to secure by United States LettersPatent is: r i a 1. Atelephone system comprising tele phone lines provided with two and threecontact jacks, a cord circuit for interconnecting said lines providedwith a plug havlikewise if connec ing three contacts, a switching relayconnected to the third contact of said plug and operated responsive to aconnection of said plug to said jack for electrically" connecting saidthird contact and a talking contact of the associated plug to supplytalking current through the winding of s aid switching for re 'isterinwith said Tacks talk is v e r a two of the v plug contactsand aswitching relay connecte ed to the third contact of the 'plug, saidswitch ng and l cut-ofi relays being energized respons ve toaconnecti'on oftlie plug and jack, said switching relayhaving contactsclosed" responsive to its ener'gization for electrically connecting oneof said plug talking contacts to the said third contact thereof tosupply current through the winding of the switching relay to theconnected line. 7

3. A telephonesyste n comprising telephone lines' having three sonnetjacks, a cut-ofi' relay connected: to one ofthe jack contacts andlineconductors extending from theother two contacts thereof, a cord circuithaving a three-contact "plug for registering with said jacks, talkingconductors extending from two of the plug contacts and a switchingelectromagnet connected to the third contact of the plug, a source ofcurrent connected to the winding of said switching electromagnet wherebysaid switching magnet and "cutoff relay are energized responsive tojaconnection'of theplug and jack,

and contacts controlled by said switching magnet for electricallyconnecting one of said plug talking contacts and the third contactthereof whereby talking current, is

supplied to the connected line through the winding of said switchingelectromagnet.

4. A telephone system comprising telephone lines having two and threecontact jacks, a cut-0T1" relay-normallyconnected to a contact of eachjack, a-cord circuit having athree' contact plugadapted'for connectionwith any of said jacks, a switching electroinagnet connected to onc ofsaid contacts of rue of each jack, a universal cord circuit forinterconnecting sa1d l1nes having three contact plugs adapted forconnection with any of said jacks, one of the contacts of each plugbeing adapted to register with the said jack contents to which thesource of current is connected, a switching electromagnet connected toeach such contact of the plug and connected to the other pole of saidsource whereby it is energized responsive to the connection of its plugwith one of said jacks, and means controlled by each electromagnet whenso energized for directly electrically connecting the said connectedplug contact to one of its associated contacts and for closing asupervisory circuit.

6. A telephone system including telephone lines having three contactjacks, a cut-off relay connected to one of the ack contacts, a cordcircuit having a three-contact plug for registering with said jacks, aswitching relay connected to a contact of the plug, a supervisoryrelaylprovided with a winding having its terminals connected to theother two contacts of said plug, a circuit including said switchingrelay and. said cut-oii' relay adapted to be closed responsive to aconnection of the plug and jack, and contactscontrolled by saidswitchingrelay for interrupting a circuit through the supervisory relayand for connecting one of said plug contacts to the said third plugcontact whereby current is supplied to the connected line through awinding of the switching relay.

7. A telephone system including telephone lines having three contactjacks, a cut-01f relay connected to one of the jack contacts,

a cord circuit having a three-contact plug for registering withsaidjack, a switching electromagnet-connected to a third contact of saidplug, a double-wound supervisory relay having one winding bridged acrossthe talking contacts of said plug, a circuit including said cut-offrelay and said switching relay adapted to be closed responsive to aconnection of the plug to the jack, and contacts controlled by saidswitching relay for interrupting the bridging circuit of saidsupervisory relay and for connecting one of the plug contacts to aterminal of the other winding of said supervisory relayand forconnecting the other of the talking contacts of the plug with saidswitching electromagnet.

8. A telephone system including a telephone line terminating in a jackat the cen tral exchange, a cord circuit provided with a three-contactplug for registering with said jack, a switching relay connected to thesleeve contact of said plug, an energizing circuit for said switchingrelay closed responsive to the insertion of said plug in said jack, andcontacts controlled by said switching relay for connecting saidswitching relay in multiple with another contact of said lug.

9. A telephone system including a telephone line terminating at thecentral exchange in a jack, a cord circuit provided with a three-contactplug for registering with said jack, a switching relay connected to thethird contact of said plug, an energizing circuit for said switchingrelay closed responsive to the insertion of said plug in said jack, asupervisory relay, and contacts controlled by said switching relay forcon necting one terminal of said supervisory relay to one of the talkingcontacts of said plug and for connecting said switching relay to theremaining contact of said plug.

10. A telephone system including a subscribers telephone lineterminating in a jack, an operators link circuit provided with athree-contact plug for registering with said jack, a battery, aswitching relay having one of its terminals connected to said 7 scriberstelephone line terminating in a jack, a link circuit provided with athreecontact plug for registering with said jack, a battery, a switchingrelay, and means individual to the link circuit for connecting saidbattery through said switching relay to two of the contacts of'saidplug.

12. A telephone system including a subscribers telephone lineterminatingin a jack at the central exchange, an operators link circuitprovided with a plug for registering with said jack, a battery, a relaywinding, and means individual to the link circuit responsive to theconnection of the said plug to the said jack for connecting said batterythrough said relay winding to a plurality of said contacts'of the plug.

Signed by me at Chicago, in the county of Cook and State of Illinois, inthe presence of two witnesses.

, ALVA J. CARTER. Witnesses GEORGE E. MUELLER, M. R. Roonroim.

Gopies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

